It happens every four years when the Democrats take center stage for their national convention. In 2004, we heard that we were in the midst of another Great Depression. This last week, we heard more economic doom and gloom.

It must have been disappointing news to Dems to read on Thursday that the US economy grew 3.3 percent in the second quarter. It’s hard to turn those numbers into a recession, much less a depression – but Barack Obama & Co. sure tried.

But if Democrats see disaster on every domestic front, they seem oblivious to the real threats to the United States. There was barely a word about terrorism, and scant mention of national security, at the weeklong gabfest. Wednesday, which organizers had promised would be devoted to national-security themes, barely touched on the issue.

That is unless you think Steven Spielberg and Tom Hanks are experts on national security. The Spielberg film tribute to US soldiers, narrated by Hanks, was an interesting take on America’s mission in Iraq: Apparently we sent soldiers there not to liberate the country and take down a brutal dictator, but to see how many young Americans we could maim or send home in caskets.

The most glaring omission, however, was in Sen. Joe Biden’s speech. The chairman of the Senate Foreign Relations Committee spent most of his time spinning folksy stories about his working-class background and making digs at his “friend” John McCain. Biden devoted less than a paragraph of his long, rambling speech to national security and foreign policy.

And when Obama finally took the stage at Invesco Field, he tried to sound tough on national defense largely by attacking his opponent. “John McCain likes to say that he’ll follow bin Laden to the Gates of Hell – but he won’t even go to the cave where he lives,” Obama jabbed.

Aside from the bad taste of questioning war hero John McCain‘s courage, Obama once more brought up the possibility that he’ll bomb Pakistan if he’s elected – again raising questions about whether he’s ready to be president.

“We are the party of Roosevelt. We are the party of Kennedy. So don’t tell me that Democrats won’t defend this country. Don’t tell me that Democrats won’t keep us safe,” he roared to an approving crowd. But Obama is no Roosevelt. And not even an outdoor sports arena reprise of JFK’s 1960 acceptance speech will fool anyone into believing that Obama is a Democratic hawk like Kennedy.

Democrats had a week to describe how Barack Obama would step into the role of commander-in-chief come January. They failed.